This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines may combust a mixture of air and fuel in cylinders and thereby produce drive torque. Air and fuel flow into and out of the cylinders may be controlled by a valvetrain. Controlling air flow into the cylinders to generate swirl or tumble flow may enhance combustion at some operating conditions. Swirl and/or tumble flow may be generated by providing an obstruction in the intake air flow path. However, combustion at other operating conditions may benefit from an unobstructed intake air flow path.